Method and means for opening bags



Jan. 15, 1952 w. E.H1GG1NBOTTOM METHOD AND MEANS FOR OPENING BAGS 8 Sheets-Sheet 1 Filed Aug. 8, 1945 Jan. l5, 1952 w. E. HIGGINBOTTOM 2,582,381

METHOD AND MEANS FOR OPENING BAGS# Filed Aug. e, 1945 s sheets-sheet 2 gmc/whom Jan. 15, 1952 W. E. HIGGINBOTTOM METHOD AND MEANS FOR OPENING BAGS 8 SheecS--Sheerl 5 Filed Aug. 8, 1945 Jan- 15,1952 w.vE. HIGGINBoT-rom 2,582,381

, METHOD AND MEANS FOR OPENING BAGS Filed Aug. 8, 1945 8 Sheets-Sheet 4 me/whom" /7//0//7 Mg/waff@ Jan. 15, 1952 w. E. HxGGlNBoTToM 2,582,381

METHOD AND MEANS FOR 'OPENING BAGS Filed Aug. 8, 1945 8 Sheets-Sheet 5 Jam 15, 1952 w. E. HIGGINBoTToM METHOD AND MEANS FOR OPENING BAGS 8 Sheets-Sheet 6 Filed Aug. s, 1945 l I I a? I II l l l l l Jan. 15, 1952 w. E. HIGGINBOTTOM 2,582,381

METHOD AND MEANS FOR OPENING BAGS Filed Aug. 8, 1945 8 Sheets-Sheet 7 Jan- 15, 1952 w. E. HIGGINBOTTOM 2,582,381

` METHOD AND MEANS FOR OPENING BAGS Filed Aug. e, 1945 f s sheets-sheet s 'il 9M I www Patented Jan. 15, 1952 U N I TEDv :STATES NT F I CE 2,582,381 :.:METHDANDS MEANS FOR, GPENING BAGS Willian E Higginbottom, Newark, Nj. J'., .assigner to" Benjamin' C: Betner' Company',-Devon;` Pa.,

a corporation'fof Delaware Application August 8, 1945, Serial No. 609,621

(Cl'."`53'-8i 7 claims.

,..=..,It isi.V an object .of thisy invention .to provide -..apparatus for withdrawing. consecutive .bags from 1 a magazine, opening the. same, and inserting vthem into consecutively presented cartons.

@It is afurther objectof vthisinventi-on to provide an improved-means. for opening `fully the ....bottoms and bodies-of .bagsfwhich have-been .closed by a single transverse .bottom seam.

.ulti` is4 a `furtherobject .of vthis `invention .to

s' ipr'ovide an improved..method ofzy openingfsquare -Lfrtypef -gusseted bags .from flattened `condition .Whichfmethod insures'the complete-and'gpositive Yformation of arectangular bottom in a plane at f'ffrightanglestol the axis of Ithe bag body.

..Tfheabove` and. `other objects Will,.1be. made y @'vclear: .from the following detailed description r4atakenin connection with the annexed :drawings .ein which:

' @Figure l. is a side elevation of the machine `with :certain :details of.` the. conveyor. omitted.

Lvsof the bag-magazineshowing particularlmthe :bag holding andzopening fingers.

:Fig: 8" isan enlarged detailnel'evation ofy the :1 plunger.

"vliig:v 9 is aplanview corresponding to Fig. 8." i? Fig.11 is a detailiof theipneumatic connection .-.rfal'i thetop of the plunger.

12VJ is a detailr of a portion-:of therconveyor` flrdrive.

Fig. 13 is a.detail`of.ithe"relay andvalvefor ."fcontrolling. :the i vacuum system.

Fig. .14 is a diagram illustrating thefelectrical fand. pneumatic circuits.' ofithe f machine.

*Figs 15'and 16` illustrate successful steps'fin "the withdrawal Vof valbag .from theimagazine `and l its partial opening;

f Fig'. `v17- is a perspective viewpartiallyin sec- *tion illustrating the'- formation- `of-the bottom, folds of a-squarebag;

""Figx'l is aside elevation-*of a supplementary gripping means;

:"Figs' '19 and'20 arerespectively elevation and plan View of an alternative gripper; yand .`2"Fig. v21` is a schematic showing of stillanother form of gripper.

1`. The j packaging fof many .commodities y requires ftheuse of a substantially'. rigid .cartoni andat l'-the .-samei't'ime requires'tnat the.pa'ckage possess .35 opposite` Walls ofthe rectangular. body Awith ,the

. a high degree of resistance to the penetrationfof grea'ses, Aoils; Water, and. moisture 'vaporf" The carton, being. formed Vof board 'of 'substantial .caliper is notoriously 'difficult' to 'Y render. irn- .pervious`, particularly in the region of the closure Qiiaps. vFor. this reason. it` has long been the practice tosupply such cartons with .an im- ,perviousiliner usually formed of relatively thin .lsheetvmater'ial ITO form suchl liners insidethe Vcar-'ton is an expensive and complicated -Job re- ,.during .equally expensive a'nd'complicat'ed machinery. It is innitelyA cheaperand. more'ei- ...cientl to provide liners .,iri"r the form lof .prefabricated .bags .Whichca'nbe produced ,at a costper thousand far less than the equivalent cost .of

forming a liner Within` the carton.

1. .The cheapest bagtypes are known in .the trade ...rear walls., the tube. being` closed or bottomed -either by heatgsealing together the .interiorly facingmargins of` one end of, the .tube,or `by turning one endof .the tubeagainst one `Wall.` of `the-.bagand sealing. it thereto, or .by a .combina- .tion. of such means. The square bag isprecisely ..jsim-ilar Lexcept-that. it .has gusseted -side walls -.--intermediate the frontend rear Walls. `In. either case, .,theebags are manufactured, packedand Y shippedV bundles in individually..flattened .con- 30 dition.

When a fiatfbag hasv its .body expanded torreo- .f .tangular configuration, ythe bottomv closurev seam ...is I.greaterinfflength `than either ydimension .of ;.=,theexpanded body. Thisoccasionsfthe formaftion, of `triangular 4fears 4which connect .the

.fffextremities or" the b-ottomrclosure seam. When asquarebag is expanded to a `rectangular-conf :-fguration,r therectangular dimensions of :the ex- :.panded. .bag :body..are .determined Vloy the :width "crear w'alls.

vprecisely equal vto the width of the :front and Equivalents of suchears arefform'ed,

- @hoWever; i onfthe/` interior of the bag and-- serve I tojointheapces of the gussetedfolds yfrom "Where the' same are caught in the bottomfseam to the'edgesof the side Walls adjacent theplane ofi the- Vbag bottom.

TheA proper Vcreasing andliatteningof theears fis ione of they major points Iofdifliculty in' the proper l'opening'rof either' atjor'- square bags. Thisp'roblem' isso'mewhatless severefin the case asass 3 of a at bag, since, generally speaking, it does not matter whether the externally formed ears are accurately creased simultaneously with the expansion of the bag body. Normally, upon eX- pansion of the bag body, these external ears will nevertheless extend substantially in the plane of the bag bottom, and, being external, they are readily accessible for folding either against their respective side walls or against the bag bottom. In a square bag, however, these triangular ears are internal and require accurate creasing if the bottom itself is to be accurately formed. There is no option as to the disposal of such ears which must always lie in the plane of the bag bottom superimposed upon those portions of the front and rear walls making up the bottom.

The machine disclosed herein will operate successfully upon either iiat or square bags. It was designed, however, particularly to meet certain problems peculiar to the square bag and the action of the machine will be described with reference to the handling of such bags.

Referring now to Figs. 1 and 2, the machine is composed of a base to which is secured a casting comprising side walls l2 and I4 and a front wall |6. At the upper end of front wall I6 there are formed guides I8 and 20 which define a passageway having a sliding t with an elevator member 22. A bracket 24 (Figs. 8, 9 and 10) connects the elevator member 22 to the plunger 26 by means of a clamp 28.

The plunger 26 and the elevator 22 are reciprocated vertically by means which will presently be described.

Mounted below the extremity 26 of the plunger 26 is a conveyor 50 which has been omitted from Figs. l and 2 for the purpose of clarity and is shown in detail in Figs. 3 and 4. This conveyor is intended to advance a series of already opened cartons and to bring each carton to rest momentarily directly in line with the plunger 26. The conveyor comprises a carton supporting slide 52. A pair of chains 54 run at opposite sides of the plate 52 and pass over sprockets 58 at one end of the conveyor and over sprockets 60 at the opposite end. At intervals, the chains 54 are connected by lugs 62, on each of which lugs is mounted a pusher plate '64. The chains 54 are moved intermittently whereby to advance the pusher plates 64 over the slide 52. A pair of guide rails 66 are mounted above the slide 52 and are spaced to provide a smooth sliding lit on one dimension of the cartons to be moved over the conveyor. The pusher plates 64 center on the median line between said rails. A drive sprocket 68 is mounted on the same shaft as the forward conveyor sprockets 58 and derives intermittent motion through a belt l0 from a sprocket '|2 secured to a shaft T4 which is mounted in a housing 'I6 secured to the wall |4 of the main frame. A bevel gear 18 is secured to the shaft 74 and meshes with a bevel gear 80 on a horizontal shaft 82 supported in bearings 84 and 84 in walls |2 and I4, respectively, of the main frame. The specific mechanism for actuating the shaft 82, and thereby the conveyor 50, will be described hereinafter.

The bag-feeding magazine cooperates with a suction head mounted in the main frame to provide not only a supply of bags, but means for withdrawing individual bags and preliminarily opening each bag withdrawn. These parts will best be understood by reference to Figs. 1, 2, 5, 6 and 7. Referring now to Figs. 1 and 2, there is shown a suction head |00 mounted on rods |02 to reciprocate normal to the front wall |B of the main frame. The rods |02 are spaced to clear the elevator 22 and the head |00 is reciprocated by means presently to be described. The magazine ||0 is shown generally in Figs. 5, 6 and '7, and is made up of a pair of angles ||4 defining an open bottom channel and which are supported on brackets H8. The brackets IIS are supported on cross members |8 and are adjustable there-along by means of bolts |20 which pass through slots |22 in the cross members ||8. Cross members ||8 receive support from the floor through conventional frame members |24. Guide plates |28 are secured to angles |4 to dene with the horizontal flanges of the brackets ||4 a bag containing channel.

A pusher member |30 is supported on the horizontal flanges of the brackets |4. Ahandle member |32 serves to withdraw the pusher member |30 and thus to clear the magazine for the reception of a supply of bags. On the under side of the pusher member |30 is bolted a bracket |34 to which is secured a chain |36 which passes over pulleys |38 and |40 and has at its free end a weight |42. This arrangement serves to supply a constant pressure of the member |30 against a supply of bags in the magazine.

At the delivery end of the magazine, the angles ||4 are connected by a cross bar |50 to which is secured a bracket |52 having upwardly projecting ngers |54 (Fig. '7) These ngers serve to hold the bottom edge of the bags in the magazine against the thrust of the pusher member |30. Also at the delivery end and adjacent to member |50, are mounted two vertical angles |56 to which are adjustably secured plates |58, each of which has a pair of ngers |68 projecting into the path of bags in the magazine and holding the side edges of the bags against the force of pusher plate |30. The angles |56 are joined at their upper ends by a cross piece |62 through screw and slot connections |64 which permit transverse adjustment of member |62. A plate ||6 is secured to member |62 by screws |68 passing through slot |10 in the plate |66, thus providing vertical adjustment of the plate |66 relative to the member |62 and consequently relative to the upper ends of the bags in the magazine. Plate |66 terminates in iingers |12 which project into the path of the bags and likewise serve to restrain them against the force of the pusher plate |30.

The several ngers |54, |60 and |12 cooperate with the construction of the bag and with the suction head |00 (Fig. 1) so as to permit bags to be withdrawn from the magazine, one at a time, and partially to open each bag as it is withdrawn and to present its open mouth for the reception of the plunger 26 (Fig. 1).

For proper understanding of precisely what happens, it is necessary to refer not only to Figs. 1, 5, 6 and '7, but also to Figs. 15 and 16. A conventional square bag, such as bag 200 (Fig. 15), has a front wall 202, a rear wall 204, and gusseted side walls 206. The bottom is closed by turning a portion 208 of the front Wall 202 back and securing the portion 208 to the rear wall 284. At the mouth end, the rear wall 204 has a lip 2|0 which extends beyond the terminus of the front wall 282 and the side walls 208. The bag 200 is a leading bag in the magazine and is engaged at the bottom by fingers |54, at its sides by the fingers |60, while the fingers |12 are vertically adjusted so as to engage only the lip 2|0 of the rear wall 204. On suction head |00 (Fig. l) are a plurality of suction cups |00' and the points at which such suction cups will engage the front wall 202 of the bag are similarly indicated in lFigs. 15 and 116. The head |00 advances from its vretracted position in Fig. 1 until the cups |00 contact and adhere to the wall 202 of the bag. The suction head |00 then moves back toward the fron-t wall I6 of the main frame, drawing with it the front wallv 202 of the bag. This sli-ps the bottom' 208 and the front-'wall 202 past the ngers FEI-and' i60;4 The ngers IGi then engage the rear Wall 204 while the fingers |12 continue in engagement with the lip 210. The net eiectis to open the mouth of the bag to the condition illustrated in Fig. 16. y

- Referring now to Figs. 5, 6 and 7, there is shown mounted at one end of the crossA member 462 a member 300. For simplicity of illustration, only one such member is shown, but in practice there will be twosuch members, one on each side of the magazine. Member 300 is mounted to rock about an axis 3132 and a spring 3l4 tends to hold-.the member 305- in the horizontal plane as illustrated in Fig. 7. The free end 300 of the member 300 is triangularly shaped. Any downward pressure exerted on the member 300 at any point intern'iediatethe end 300' and the axis 302 wil-l tend to rock the member 300 from its horfzontal position in Fig. '7 to a position at right angles thereto;

In Fig. 16 the members 30S are shown in their horizontal positionv with the open bag mouth just below them.v When the bag arrives at this position, the plunger 26 (Fig. 1) begins its descent and its nose 2S encounters 'the members 300 rocking them about their axes 302 thereby assuring that the side walls 206 of the bag 200 cannot possibly interfere with the descent of the plunger. This makes it possible to have the dimensions of the plunger 20 correspond very closely with the dimensions of the bag body; so closely, that it is virtually impossible for the cross section of the bag body to depart substantially y,

from a rectangle. The importance of this fact will be brought out hereinafter when the action of the. plungerl at the bottom of the bag is described.r

Referring now to Fig. 17, there is shown the completely expanded bottom 2l2 of the bag 200. One half 2M of the bottom is formed from a portion of the rear wall 201i and the other half 216 is formedA from a portion of the front wall 202. There is a transverse fold line 218 in the bag bottom marking the inner extremity of the bottom iold Ziii. A portion of the side walls 206 at each side of the bottom is folded in to form a triangular ear 220 which lies generally in the plane of the bottom and forms an extension of the side Wall 2%. Mathematically, the diagonal fold lines indicated as 22! and 22| will always make e degrees with each dimension of the bottom. When the bottom is perfectly formed, it lies in a plane at right angles to the front, rear, and side walls, and is sufficiently well defined to form a distinct meeting line such as 223. It is clear th-at the critical point lies at 224.` whichrepresents a meeting of the central line 225 of the ears with the central gusset fold line 226. The cocticn of the machine elements thus far described in unique in assuring repeated perfection of the bottom folds. The suction cups |00 on the head Iilil exerted a considerable grip on the front wall 202 and offer substantial resistance, not only to direct withdrawal of the bag wall 202 in a direction normal to the cups, but, and especially since the cups are of rubber, they offer substantial resistance to a. sliding of the bag wall across the cups in the plane of their active 4the plunger as the plunger ascends.

.6 faces. Asf heretofore described, the. plunger 26 is dimensioned so as. rather closely to fit the interior of the bag body. This closeness of t preserves the rectangular configuration of the body which under internal pressure would tend to become oval or circular as indicated by the dotted line 230 in Fig. 1'?. This in itself is of great assistance in maintaining a proper relationship in the elements of the bag bottom while it is expanded.

The plunger moves quite rapidly and its speed is such that it displaces air as it moves into the bag at a rate such as to produce a substantial static pressure between the nose'26' of the plunger and the bottom of the bag. This static pressure is substantial due to the throttling` effect of the lrelatively small clearance between the walls of the bag and the walls of the plunger. The generation of this static pressure tends to expand the bagbottom to draw it into a plane at right angles to the axis of the bag and to initiate the folds which will ultimately resultv in the ears 220. In addition and as will presently be described, a jet of air is directed axially of the plunger and emerges through the noseV 26.

In. its descent the plunger comes very close to the bottom of the bag before the bag starts to move relative to the suction cups |00. At the time the bag starts to move with the plunger, the formation of the bottom is nearly complete and the folds have been well initiated byair pressure alone and their location and direction have been controlled by the maintenance as aforesaid of the rectangular cross section. The plunger contacts the bottom of the bag before the bag leaves the suction cups. The bag is carried downward on the nose of the plunger into a carton which has been properly positioned by the conveyor 50 and continued air pressure through the nose 26' serves to strip the bag from The contact of the plunger nose with the bottom of the carton which is. resiliently supported as will hereinafter be described, serves to crease the fold lines of the ears into their final position. When these creases are established the bag bottom is forced to remain in rectangular condition in its proper plane since the diagonal fold lines act as struts or trusses for this purpose.

So far as the proper opening and expansion of thebag bottom is concerned, the fact that the bag is inserted by the plunger into a carton is immaterial, except where a flat bag, asv distinct from a square bag, is concerned. In the case of a flat bag, expansion of the bottom would form triangular ears in the plane of the bottom and extending outwardly from the side walls. If such a bag in such condition is then inserted into a closely fitting carton, such ears will automatically be folded upwardly to lie against the side walls.

Referring now to Fig. 13, there is shown a valve 500 having a connection E02 to the sucker head 420 and a connection 6&4 to the suction side of an air pump 606 (Fig. 14). A member 608 is slidably mounted in a cylinder GIG, of the valve 6&0, which cylinder is intersected by the connections 602 and 684. The member 668 has a beveled edge SI2 which seats on a beveled rim Bit in the cylinder 6H). With the parts in the position shown in the Figure 13, the beveled edge |2 of the member 608 and the beveled seat 6M of the cylinder Bill' have air-tight mutual Contact. Ii the member 608 drops below the position shown in Fig. 13, it -exposes openings GIG in the cylinder 6|0, thus permitting air to be drawn freely through the connection 604, thus preventing the occurrence within the cylinder 6|0 or in the connection 602 of any substantially subatmospheric pressure. The member 608 has an internal recess 6I8 in which is seated a spring 620 which bears against the top 622 of the cylinder 6|0, and tends to maintain the member 608 in its lowermost position with the openings 6|6 in communication with the connection 604.

The member 608 has mounted in its lower surface a knob 624 which bears on one end 626 of a bell crank or lever 628. The bell crank 628 is pivoted at 630 and, at its opposite end, is connected to a link 632 which in turn is pivoted to the armature 634 of a solenoid 636. When the solenoid 636 is energized, the armature 634 is drawn downwardly, rocking the bell crank 620 and raising the plunger 608 until its beveled edge 6|2 engages the seat 6|4 of the cylinder 6|0. If then the suction cups engage the wall of the leading bag in the magazine, a vacuum is established in the line 602 and in the cylinder 6 0. This vacuum is sufficient to hold the plunger 600 in its uppermost position against the force of spring 620, even though solenoid 636 is de-energized to drop the end 626 of the lever 628 away from the knob 624 of the plunger 668. If then the plunger 26 removes the bag from the suction cups |00', the vacuum is broken and the spring 620 restores plunger 608 to its lowermost position, thereby clearing the passage between the openings 6|6 and the connection 604.

Referring now to Figs. 8, 10 and 14, it will be seen that the plunger 26 has a conduit 26 extending its entire length and penetrating its nose 21. A flexible hose 28 connects the conduit 26 to the delivery side 607 of the pump 606. The suction side 601 of the pump 606 has a hose connection 640 joining the pump 606 to the connection 604 of the valve 660. while a flexible hose |0| joins the connection 662 of the valve 600 to the suction cups |06. The solenoid 636 is connected to a source of electricity 650 through a switch 652. The switch 652 is operated by means of an arm 653 (Figs. 3 and 4) which is interposed adjacent the conveyor 56 to lie in the path of cartons advancing on the conveyor. The switch 652 is closed and the solenoid 636 is energized only when a carton passes the lever 653. This is timed to take place just before the suction head |00 completes its advancing movement toward the bag magazine. On closure of the switch 652, the solenoid 636 is energized, and the valve member 608 is raised to close oi the channels 6|6 and to seat the rim 6 I 2 of member 608 as above described. This applies suction to the head |60. During the time that it takes the carton to pass the lever 653. the suction head |00 makes contact with the leading bag in the magazine and the cups |00' adhere firmly to the bag. From this point on, it is no longer necessary to hold the switch 652 closed and, in fact, a moment after the suction cups |00' establish, through contact with the bag, subatmospheric pressure within the valve 6 0, the carton passes the lever 653, permitting switch 652 to open, and breaking the circuit of the solenoid 636. As previously stated, however, the valve member 608 remains in its upper position under the force of vacuum.

When the suction head has reached approximately its most withdrawn position from the magazine, the plunger 26 begins its descent, enters the now open bag. and upon reaching approximately the bottom of the bag, slides the bag ol the suction cups |00. This breaks the vacuum in valve 6|0, permitting the valve inember 608 to move to its lower-most position under the thrust of spring 620. This opens the passages 6|6 permitting air freely to be drawn'through the pump 606. This free delivery of air moves through the hose 28 to the nose 21 of the plunger 26. The flow starts a moment before the plunger, carrying the bag, strikes the conveyor 50. During this interval, the delivery of air assists in forming the bottom folds of the bag end, as the plunger starts to rise, the air delivered through the hose 28 and the conduit 26" strips the bag from the plunger, permitting the bag to remain within the carton. If desired, an accumulator can be placed in the line of the hose 28 so that a substantial pressure and a substantial supply of air can be built up during the period when the valve member 608 is at its lowermost position and the channels 6 l 6 are open. In such case a valve is provided between the accumulator and the plunger 26, and is made responsive to the descent of the plunger. As a rule, this will only be necessary Iwhen relatively large bags are handled, or when the material of the bags is porous.

The arrangement of valve, solenoid and pump, above described, has, as its primary function, prevention of the removal of the bag from the magazine, unless a carton is on the conveyor and ready to receive the bag. A collateral function, however, is to provide maximum delivery of air through the plunger 26 at the time when it is most needed, that is, just before the plunger strikes the conveyor and while the plunger is being withdrawn.

The drive by which the various elements heretofore described are operated may best be understood by reference to Figs. l, 2, 3, 4, 11 and 12. A motor 400 drives the main shaft 402 through a pulley and belt arrangement 404. A pinion 406 on shaft 402 meshes with a gear 408 on a counter shaft IHS. A pinion 4|2 on the counter shaft 4|0 meshes with a gear 4|4 on a cam shaft 4|6. The gear 4|4 is connected to the shaft 4|6 by means of a one-revolutiion clutch 4|8, and is operative to drive the shaft 4|6 only when a pin 420 is disengaged from a lug 4|8 on the clutch 4|8. This pin is under the control of a hand lever 422, which affords a means of disengaging the motor from the cam shaft, but which always brings the parts to rest in a position predetermined by the location of the lug 4|8 relative to the reciprocating mechanisms.

A pair of cams 424 and 426 are keyed to the cam shaft 4|6. The cam 424 controls the suction head |60, while the cam 426 operates in plunger 26. A bell crank 428 is pivoted to the frame at 430 and has at one end a follower 432 engaging a groove in the cam 424. At its opposite end, the bell crank 428 is connected to a rod 434 which is pivoted at 436 to a bracket 438 to which the rods |02, which carry the suction head |00, are mounted. A spring 440 relieves the rearward movement of the bell crank 426. This permits the use of adjustable stops to limit rearward movement of the suction head |00. A collar 442 is mounted on the rod 434 to receive the forward thrust of the bell crank 420. Adjustment of the collar 442 on the rod 434 provides a means for determining the extent oi' the forward advance of the suction head |66. A lever 450 is pivoted to the frame at 452 and, at a point intermediate its extremity, has a follower 454 which bears in a groove in the cam 426. At its free end, lever 4 50 has 'fl-glial? Segment?. 4.55 Whh' ltell@ Wim@ Pinion .458 on e shaft dell e gear 4621s also ,sev eured to they .shaft 4611 and meshes with a pinion 46,4 on a shaft 466. A gear 4681s, also secured to the shaft 465 and meshes with a1 rack` 4111` secured to the elevator 212. As the: lever 450 is rooked lov the cam e2@ and the follower 454, it oseillates erst, shaft dei?. thenv shaft .dea and thereby raises and lowers the. elevator Z2 and .the plunger 2e. The shafts ed@ and `15.6 with tlld goed' 462 and the pinion 464 provide through substituuons of the gear and pinion. means for adjusting the stroke .of the plunger 26.

A sprocket. i12 is keyed to. the shaft 4t2, and drives the pump 6,66 through a Chain .416. @1.1.51 a sprocket 416.

011el end of the shaft el@ extends through the side frame i2 and nas mounted thereon. en. arm 500 (Figs. 3 and 12). The arm 500 is pivoted at 502 to one end of a connecting rod 56d, the opposite end of which is pivoted-at 65.6 to aleyer 588 which is rotatably mounted all il@ on the shaft 82- A dise `SI2 is keyed to the .shaft t2 and has in its periphery .equally spaced note/lies 51.4. At the opposite end of the lever 568 is pivotally mounted a pawl l6. As the lever 66d lrotates With the shaft GIE, the lever 553 is .oscillated about the shaft 82 by the ,connecting rod ,6.64. During the forward voscillatory movement, the pawl 66 engages one of thenotches 61d in the disc 52, thereby advancing,l through a predetermined rnumber o f degrees, theshaft, as heretofore noted, advances the conveyor It will be seen, therefore, that 4there is one ad: Vancing movement of the conveyor 56 foreach rotation of the shaft M6, just as there is also one lowering andraising ofthe plurlgdl 25, one advance and, retreat .of vthe .suetiol yheed. ld. .for the same revolution of ,shaft .4!5 The Shaft 82, and accordingly the conveyor 50 are, how.- ever, idle during more than onefhalf of eacljl revolution of the sha-rt sie to permit .the ,Cartons on the conveyor to remain stationary while the plunger et inserts .a baeloto V.the .darten below it at ,the time.

It would reduite ,miorometric adjustment, einen would be both expensive to provide and time eolie suenos to operate, to essere that the nose 2t. of the plonger 2t would .never .fertility eooodoter the Ibottom of the carton resting the tolereren As a practical matter, therefore, means `are provided for yielding to the shocl; of the encounter of the plunger 26 with the conveyor 66. This mechanism is best shown in Figs. l and 2 and comprises a pair of rods 66 mounted in bosses 162 in the base lil. At their upper ends, the rods 100 are secured in bosses 104 formed on the guide E6 'for the elevator 22. A paii` of cross members H36 arevslidably mounted on the rods la@ and are rigidly secured to a l; -shaped member "ma which lies below the elevator 22 and between the rods 166. A rubber or other resiiientvpad -l' lil cushions the bottom of the U-shaped member F68 against the impact of the elevator 22. Compression springs H2 surround the rods H36 below the lowerrnost of the cross members '66 to afford resilient support for the member lds. rlhe actual energy of the plunger and elevator are absorbed by this structure and it is only necessary to provide below the :belt of the conveyor 5i] in the area of impact of the plunger 26, a yielding plate to accommodate the movement of the plunger. This need only be lightly sprung since the inertia load is taken Yup by the springs 11.2.

n case it is desired to use the machine merely as a means for opening the bagsand squaring up bag bottoms without inserting the saine into cartons or in any case where the material of the bag is relatively stiff, it is desirable to supplement the coaction of the plunger with the grip of the suction cups 66 by the use of certain supplementary means best shown in Figs. 18, 149 and 20, and best understood by reference to said -gures in conjunction with Figs. 5, 6 and 7.

As heretofore described, when the plunger 26 approaches the open mouth of the bag, the front Wall of which is gripped by suction cups Illily and the rear wall of which is `gripped by iingers |54, |66 and |12 (Fig. 16), it strikes the members 300' (Fig. 7) turning them through 90 degrees from their normal horizontal position to a vertical position, and in so moving, the members 366', square up the mouth of the bag and serve as a guiding means to prevent any engagement of the noseof the plunger 26 with the gusseted side walls of the bag. in the case of small bags formed of relatively flexible material such as glassine or cellophane, the grip of the suction cups is sufficient to hold the bag in position until the plunger 2.6 so nearly reaches the bottom of the bag as to complete the bottom folds illustrated in Fig. 17. The descent of the plunger then slides the bag past the suction cups |00 and releases the bag vfrom the grip of the cups. Where the material is relatively sti, such for example, as certain laminated glassines and certain paper and Yfoil laminations, the resistance offered by the suction cups Ille may not be sufficient to ent able Vthe plunger 26 firmly to ydel'ne the requisite areas at the bottom of the bag before pulling the bag away from the suction cups |00. To meet this condition, the present invention contemplates the use of auxiliary pressure members which frictionally engage the outer surface ofthe side walls, pressing these walls against ktheside walls of the plunger. The coeicient o f friction of these pressure members with respect to the material of the bag is greater than thecoefcient of friction between the material of the bag and the material of the plunger or of the members 300, so that despite the applied pressure, there is no substantial wear of the inner surface of the bag walls.

As shown in Fig. 18, there is provided a meniber 800 of rectangular cross section and having a reduced rearwardly extending ange 802. A cylindrical bore 304 extends lengthwise of the member 800 and receives a cylindrical `stud 806. At the rearward end of the stud 856 is -a reduced threaded portion 808 on which are mounted lock nuts 8|IJ. The body portion 866 is drilled trans- Versely at 8l2 and a portion of `the body of the stud B06 is cut away at 814. A pin passes through the hole SI2 and serves to lock the stud 806 against turning movement and also to limit axial movement of the stud in the bore 804. The forward end of the stud 866 is reduced at 816 and passes through the center of a rectangular plate M8. The end 8|6 of the stud B06 is riveted' into a countersink in the plate tllS. A disc 326 of rubber or other high friction material is secured to the outer face of the plate 818 by means of screws and nuts 822. The fia-nge is drilled and tapped at 824 so that the member 866 may be secured to a support 626 'by means of cap screws 828. The support 626 is screwed by any suitable means to the vertical angles |56 (Figs. 5 and 7). A spring 636 encircles the forward end of the stud 8l6 and contacts the body portion 860 and the plate 8l8, tending to thrust the stud 806 forwardly. The forward movement is limited l1 bythe lock nuts 8I0 which also serve to adjust the tension of the spring 830.

Two such members are provided, one for each side of the bag and are positioned to engage the bag preferably above the extremities 300 of the members 300 when the same have entered the bag.

An alternate structure is illustrated in Figs. 19 and 20 and comprises a member 900 having a boss 902 formed at its forward end. The boss 902 is drilled at 904 for the reception of a stud 906. A bell crank 908 is bifurcated to form arms 9I0 and 9I2. These arms are fulcrumed on the stud 906 and at their free ends have mounted a stud 994 on which a roller 9I6 is rotatably mounted. The opposite end 9I8 of the bell crank 908 is drilled and tapped for the reception of a cap screw 920 bearing a lock nut 922. The cap screw 920 penetrates the end 9I8 of the bell crank 908 and bears against the member 900. At the extremity of the end SIB there is a tapped hole 924 which receives a cap screw 926. The cap screw 926 penetrates a bore 928 in the member 900 and a spring 930 encircles the cap screw 926 and bears yagainst the head 926 of the cap screw 926 and against a washer which in turn bears against the member 900. The spring 930 tends to hold the nose of the cap screw 920 against the member 900 and therefore to limit the forward swinging of the roller 916 about the stud 996. The outer end of the member 900 is drilled and tapped at 932 to enable the assembly to be secured to a support 934 by means of cap screws 936. The support 934 is secured by any suitable means to the angles IE6 shown in Figs. 5 and 7.

The mounting of the roller 9 I 6 is such that any turning of the roller on the stud 9M is subject to strong frictional resistance and the roller GIB has its cylindrical surface covered with rubber or other suitable high friction material. The resistance to turning of the roller 9I9 on the stud 9M is adjusted to a point at which the roller will rotate before the limit of strength of the bag wall is reached, or before the bottom can be destroyed by downward movement of the plunger 26. The roller thus affords a safety factor which will prevent destructionof the bag even though, by adjustment of the cap screw 920 and the spring 930, an excess of pressure is brought about between the roller SIB and the bag wall.

In addition to or as an alternative for the expedients illustrated in Figs. 18, 19 and 20, resort may be had to the device illustrated in Fig. 2l. Where the friction plate or roll shown in Figs. 18, 19 and 20 is replaced by a pair of suction cups 952 mounted on a pair of supporting members 959 and each connected by means of conduits 954 with the branch 602 of the valve 600. This arrangement applies suction to the cups 952 simultaneously with the application of suction to the cups I of the reciprocating head I00 and breaks suction to the cups 952 simultaneously with the breaking of suction to the cups I00. The particular advantage of this expedient is that it does not involve the generation of friction by pressure applied against the plunger 26 through the walls of the bag 956. Instead, the side walls of the bag 955 are drawn outwardly and away from the walls of the plunger 26 thereby completely avoiding any rubbing or scufng of the interior surface of the bag walls.

The claims hereafter set forth are directed not only to the combination of a carton advancing conveyor, a bag magazine, suction head and plunger, but are also devoted to sub-combinations l2 of the plunger andA bag opening means, and to the plunger, the bag opening means, and the suction control valve. These subsidiary combinations have distinct utility and it is anticipated that the subject matter of such sub-combinations will be independently incorporated in various types of machines quite apart from a carton delivering conveyor. Unless otherwise specified in the claims, any reference to bags shall include fiat and square bags, and flat or gusseted tubes.

What is claimed is;

1. A method of expanding gusseted bags of the square type from flattened condition comprising: opening the mouth of the bag and thereafter progressively expanding the body of the bag toward the bottom while restraining the bag walls in mutually rectangular relationship, initiating the bottom fold lines by pneumatic pressure exerted concomitantly with the progressive expansion of the bag body and then creasing by positive compression, the fold lines thus initiated.

2. A machine of the class described comprising: a magazine for holding a quantity of bags; means for moving the outermost wall of the leading bag in the rnaffaf/ine: means restraining the opposite wall of said bag against movement whereby to open the bag mouth; means entering said opened mouth and operative to remove the bag from said wall moving and wall restraining means: and guide means entering said bag mouth simultaneously with said bag entering means, said guide means entering adjacent the side walls between the leading and trailing walls and being operative to assure rectangular configuration of the open bag mouth.

3. A machine of the class described comprising: a magazine for holding a quantity of bags; means for moving the outermost wall of the leading bag in the magazine; means restraining the opposite wall of said bag against movement whereby to open the bag mouth; means entering said opened mouth and operative to remove the bag from said wall moving and wall restraining means; and guide means entering said bag mouth simultaneously with said bag entering means, said guide means entering adjacent the side walls between the leading and trailing walls and being operative to assure rectangular configuration of the open bag mouth, said guide means normally lying in the path of said bag entering means and being operated thereby.

4. A machine of the class described comprising: a bag magazine; a suction head for opening consecutive bags thereon; a plunger for entering the bags removed by said Suction head to expand the bags and carry them below said suction head; a conveyor for presenting cartons consecutively to a position below and aligned with said plunger to receive bags delivered thereby; a pump having its suction side connected to said suction head; a valve in the suction line of said pump and means responsive to the absence of a carton at said position for operating said valve to disable said suction head.

5. A machine of the class described comprising: a bag magazine; a suction head for opening consecutive bags thereon; a plungerv for entering the bags removed by said suction head to expand the bags and carry them below said suction head; a conveyor for presenting cartons consecutively to a position below and aligned with said plunger to receive bags delivered thereby; a pump having a suction line connected to said suction head and a delivery line connected to said plunger; a valve in said suction line;

means responsive to the absence of a carton at said position for operating said valve to disable said suction head; and means responsive to the removal of a bag from said suction head for connecting said suction line to the atmosphere whereby to deliver air to said plunger for stripping a bag therefrom.

6. A machine of the class described comprising; means for opening the mouth of a bag; a plunger; means for inserting said plunger into said open bag mouth; and means operating at right angles to said bag opening means for gripping frictionally two opposed walls of the bag against the plunger as the plunger enters the bag.

7. A machine of the class described comprising: means for opening the mouth of the bag; a plunger; means for inserting said plunger into said open bag mouth; and means operating at right angles to said bag opening means for gripgo REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 954,739 Joplin Apr. 12, 1910 1,001,268 Heybach Aug. 22, 1911 1,527,030 Delamere et al. Feb, 17, 1925 1,943,770 Morey Jan. 16, 1934 2,106,463 Long Jan. 25, 1938 2,299,699 Hultkraus Oct. 20, 1942 2,342,219 Price Feb. 22, 1944 2,357,527 Lundquist Sept. 5, 1944 2,428,192 Berch Sept. 30, 1947 

